What turbo for 410ci stroker?
07-07-2012, 09:01 AM
#21
If it was running race gas all the time I would build it for as much power as I possibly could which would most likely still involve a similarly sized cam.
If you wanted 10.5:1 static compression the dynamic would need to be in the low 8's to keep it happy with pump gas and not be overly timing sensitive.
Normal sized cam is kinda a blanket statement especially when it comes to strokers and big turbo's.
People have seemingly come to the conclusion that they need a small turbo so that it will still spool fast on their car and then stick an off the shelf cam in it or one that is totally wrong for the application and are seemingly happy when they could of used a bigger turbo, made more power and if they used the right cam for their application it would of spooled just as fast if not faster and not had ridiculously high discharge temperatures because the turbo is too small and being over worked on the size motor it's being used with.
Really I can't answer that question with a general statement as every set-up is different and will require a different camshaft.
07-07-2012, 10:54 AM
#22
If it was running race gas all the time I would build it for as much power as I possibly could which would most likely still involve a similarly sized cam.
If you wanted 10.5:1 static compression the dynamic would need to be in the low 8's to keep it happy with pump gas and not be overly timing sensitive.
Normal sized cam is kinda a blanket statement especially when it comes to strokers and big turbo's.
People have seemingly come to the conclusion that they need a small turbo so that it will still spool fast on their car and then stick an off the shelf cam in it or one that is totally wrong for the application and are seemingly happy when they could of used a bigger turbo, made more power and if they used the right cam for their application it would of spooled just as fast if not faster and not had ridiculously high discharge temperatures because the turbo is too small and being over worked on the size motor it's being used with.
Really I can't answer that question with a general statement as every set-up is different and will require a different camshaft.
If you wanted 10.5:1 static compression the dynamic would need to be in the low 8's to keep it happy with pump gas and not be overly timing sensitive.
Normal sized cam is kinda a blanket statement especially when it comes to strokers and big turbo's.
People have seemingly come to the conclusion that they need a small turbo so that it will still spool fast on their car and then stick an off the shelf cam in it or one that is totally wrong for the application and are seemingly happy when they could of used a bigger turbo, made more power and if they used the right cam for their application it would of spooled just as fast if not faster and not had ridiculously high discharge temperatures because the turbo is too small and being over worked on the size motor it's being used with.
Really I can't answer that question with a general statement as every set-up is different and will require a different camshaft.
07-08-2012, 05:51 PM
#26
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I beg to differ.
With the right cam and 10:1 CR it will not be hard to spool at all especially with a 410 stroker I still don't understand why people are so scared of lag. It's tossed around and made out like if you don't buy a turbo that is smaller than what you think you need it wont spool fast.
Old school and not the correct way of thinking.
OP you will need a cam change though as that cam is totally wrong for boost although I really like HUC lobes for boost the valve events are way off for boost.
Something like 247/251 .632/.632 115+3 on HUC lobes would work well with your super victor intake, and any of the turbo's I listed above while keeping the dynamic compression down enough with a late enough IVC to use pump gas and take advantage of that single plane you have already.
With the right cam and 10:1 CR it will not be hard to spool at all especially with a 410 stroker I still don't understand why people are so scared of lag. It's tossed around and made out like if you don't buy a turbo that is smaller than what you think you need it wont spool fast.
Old school and not the correct way of thinking.
OP you will need a cam change though as that cam is totally wrong for boost although I really like HUC lobes for boost the valve events are way off for boost.
Something like 247/251 .632/.632 115+3 on HUC lobes would work well with your super victor intake, and any of the turbo's I listed above while keeping the dynamic compression down enough with a late enough IVC to use pump gas and take advantage of that single plane you have already.
i have over 20 years experience in turbo cars from hondas to single turbo vipers to a ford GT TT and quite a few supras in between as well as ls1's personally....not counting the other friends with turbo cars ive helped.
heres a viper with a 106 and tall gearing (2.73s) we did it made 1022 on pump 8-9psi at 5200rpm we slowly went up in rpm while tunning...started run at 1000rpm (car revved to 6800 6 speed)
back to car at hand
1. he didnt state he was willing to change his cam or setup (heads converter etc etc)
2. he has a heavy *** car add a iron block (peaky cam and large turbine you have issues period.
3. his car is RPM limited (singles tend to to like rpm) as most stroker street ls motors are.
4. its not a race car it has to be streetable.... when u give it gas it moves!
to illustrate my point ill just use a few links and quotes
http://shop.virginiaspeed.com/category.sc?categoryId=33
i dont see a large duration or overlap cam in here and im sure they dont wanna sell a shitty cam to the public either. comp cams and others have similar ideas on turbo cams..
http://www.hotrod.com/pitstop/hrdp_1...s/viewall.html
"Another factor influencing cam design for a turbocharger is charge density. Because turbo applications make such dramatic power, the common misconception is that the intake and exhaust port velocities need to be quite high, in turn mandating very large-duration camshafts to make a given amount of power. Actually, the exact opposite is true. Because of the increased pressure along with a corresponding increase in oxygen and fuel density, more fuel and air are moving into the chamber, but the velocity is actually lower. The combustion chamber pressure therefore rises more quickly, and filling occurs earlier in the stroke compared with a similar NA application.
............Put all this together, and what works best in a turbo application is a smaller camshaft than the profiles normally specified for NA engines"
"Since the exhaust stroke generally can not be expanded into the intake stroke, due to the increased probability of valve to valve and valve to piston intersection during the valve overlap period, degrees are usually subtracted from the power stroke. If a long duration exhaust cam is, say, 20 degrees longer than stock, usually it also makes the power stroke become 20 degrees shorter than stock.
For example, a Ford 302 has a 3" stroke. If the stock exhaust cam forces the valve open at 70 degrees BBDC (before bottom dead center), the power stroke is 2.013". If the long duration exhaust cam opens the valve only 20 degrees earlier (in order to add 20 degrees of exhaust duration) the power stroke is reduced to 1.5". The long duration exhaust cam, with just 20 degrees more duration, has reduced the power stroke by .513"! That is the opposite effect of a 1/2" stroker kit!
People spend thousands to put even a 1/4" stroker crank in their engine, to make more power. You've just done the opposite. You've just cut your stroke by 25%. All else being equal, you can expect to lose about 25% of your engine's thermal efficiency (its ability to convert heat (thermal energy) into horsepower (mechanical energy))."
SOME MORE GOOD READING
https://ls1tech.com/forums/forced-in...version-5.html
that cam of his is his problem so unless he decides to change it he is limited to what will work...
07-09-2012, 08:58 AM
#27
I would go with a GT50-88 or GT55-88 or 91. Either will feed that motor. The GT50 is the new kid on the block. Probably one of the best street turbos we have ran on LS based engines in a long time. Also the S400-HP88 is a killer piece as well. Its been making power for many years.
